PROBLEM TO BE SOLVED: To provide a photoacoustic imaging apparatus and a photoacoustic imaging method capable of further improving the sensitivity of muti-photon photoacoustic wave detection, and obtaining a clear image at a deep region of a living body.SOLUTION: A photoacoustic imaging apparatus for visualizing a body interior to be measured by using a photoacoustic effect comprises: a) a plurality of pulse laser irradiation means having different pulse widths for inducing multi-photo excitation by condensing the pulse laser and irradiating a body to be measured with the pulse laser b) means for performing arithmetic processing of a plurality of photoacoustic waves generated from the body to be measured by a plurality of excitation light pulses having the different pulse widths, and imaging the body interior to be measured (here, the arithmetic processing includes time integration, peak extraction, and frequency component extraction) and c) display means for displaying an image obtained by the imaging means.
